a. -15 . 999 
=-14985
b. 121. (-63) +63 .(-53) -63.26
=-7623+(-3339)-1638
=-10962-1638
=-12600
c. [299. (-74) + (-299) . (-24)] : (-50).
=[-22126+7176]:(-50)
=-14950:(-50)
=299
d. [900 + (-1140) + 720 ] : (-120)
=[-240+720]:(-120)
=480:(-120)
=-4
e. 6. (-4 2 ). (-102 ) : 24 
=-252.(-102):24
=25704:24
=1071
f. [(-8).(-8).(-8).(-8) + 84 ] : 8100
=[64.(-8).(-8)+84]:8100
=[-512.(-8)+84]:8100
=[4096+84]:8100
=4180:8100
=0,51

Bài 2:

a)38.63+37.38=38(63+37)=3800

b)12.53+53.172– 53.84=53(12+172-84)=5300

c)35.34+35.38+65.75+65.45=35(34+38)+65(75+45)=2520+7800=10320

d)39.8 +60.2 +21.8=8(39+21)+120=480+120=600

e)36.28+36.82+64.69+64.41=36(28+82)+64(69+41)=3960+7040=11000

a)38.63+37.38

=38.(63+37)

=38.100

=3800

a) \(=38\left(63+37\right)=38.100=3800\)

b) \(=53\left(12+172-84\right)=53.100=5300\)

c) \(=35\left(34+38\right)+65\left(75+45\right)=35.72+65.120=10422\)

d) \(=39.8+15.8+21.8=8\left(39+15+21\right)=8.75=600\)

e) \(=36\left(28+82\right)+64\left(69+41\right)=36.110+64.110=110\left(36+64\right)=110.100=11000\)

0,37 + 37/50 + 26% + 63/100

= 37/100 + 37/50 + 13/50+ 63/100

= ( 37/100 + 63/100 ) + ( 37/50+ 13/50 ) 

=                  1           +         1

=                                  2

= (0,37 + 63/100) + ( 37/50+ 26%)

= 1+1

=2

0,37 + 37/50 +26% +63/100

=37/100 + 74/100 +26% +63%

=37% + 74% +26% + 63%

=(37% + 63%) +(26% +74%)

=100% + 100%

=200% 

                                                                    MIK NHA !!!!!!!!!!!!!

Đáp án cần chọn là: C

a: =-38x100=-3800

          Bài làm :

Ta có :

Vì 4/59 < 4/53

\(\Rightarrow\frac{63}{59}< \frac{57}{53}\)

Vậy 63/59 < 57/53

63/59 = 1 + 4/59 

57/53 = 1 + 4/53 

Vì 4/57 < 4/53

Vậy 63/59 < 57/53 

Ta có

\(\frac{63}{59}>1;\frac{57}{53}>1\Rightarrow\frac{57}{53}>\frac{57+6}{53+6}=\frac{63}{59}\)

Hok Tốt !!!!!!!!!!!

= 42/63 + 2/63 + 14/105 + 6/105

= 44/63 + 20/105

= 8/9